I needed a gps for my bike, and i did not want to spend 200€ on a gps + 80€ for mounting hardware. And a iPhone holder would cost me 50€. So i decided to build one, it will work for most smart-phones as long as you can by a "case" for them.
Step 1: What you need
# You need a hi quality case, i bought mine really cheap ( 5€ ) it's a aluminium case.
# A old mountain bike reflex.
# Epoxy glue!
Step 2: Start preparing the case for glue
Put it to the back of the case and draw around it.
Then use fine sandpaper to take away the glue so the glue gets a firm grip.
then put the sand paper on the case with the "sandy" side out, the start sanding down the side on the reflex mount that we’re going to glue so it fits perfectly on the backside of the case.
Step 3: TIME FORE GLUE !
try to line it up straight !